package org.example.ch02.p21;

public class Main {
    public static void main(String[] args) {
        double result = 4 * (1.0 - 1.0 / 3.0 + 1.0 / 5.0 - 1.0 / 7.0 + 1.0 / 9.0 - 1.0 / 11.0 + 1.0 / 13.0);
        System.out.println(result);
    }
}
